1. Field of the Invention
The preset invention relates to a structure for axially supporting a propeller shaft of an automotive vehicle by a center bearing.
2. Description of the Related Art
Generally, a propeller shaft is any supported by an annular supporting member by connecting an inner ring to an outer ring via an elastic member, through a center bearing. The center bearing is supported at its outer race by the inner ring of the annular supporting member. However, when front and rear openings of the inner ring are opened, dirty water, salt water, foreign matter or the like enters into the center bearing, thereby interfering with the bearing function, which may cause seizure or noises.
In one example, a flange is integrally formed with a stopper piece press-fitted on the propeller shaft to position and fix the center bearing at a predetermined axial position, and the opening of the inner ring is covered with the flange.
This example is shown in FIG. 4 In FIG. 4, a propeller shaft 01 is axially supported through a center bearing 05 by an annular supporting member 010 obtained by connecting an inner ring 011 to an outer ring 012 via an elastic member 013. The center bearing 05 is fitted on the propeller shaft 01 at a predetermined position inside the inner ring 011. One end of an inner race thereof abuts on a step portion of the propeller shaft 01, and the other end thereof is pressed by a stopper piece 06 made of a steel member press-fitted on the propeller shaft 01, so that the center bearing 05 is positioned in an axial direction and fixed.
As mentioned above, the inner ring 011 of the annular supporting member 010 supporting the center bearing 05 therewithin has openings in front and rear portions. A rear opening is covered with an expanded large diameter portion of the propeller shaft 01 and a front opening is covered with a flange 06a integrally formed on the stopper piece 06, thereby preventing dirt water or the like from entering into the interior of the center bearing 05 as much as possible. In the interior of the inner ring 011, the front and rear portions of the center bearing 05 are sealed by seal members 07 and 08. Dirty water is prevented from entering as much as possible by covering the front and rear openings of the inner ring 011 as described above, thereby increasing the sealing effect.
Since dirty water or salt water tends to splash on the flange 06a of the stopper piece 06 part ay covering the front opening in the inner ring 011, the flange 06a is subject to severe corrosion. In the worst case, there is the possibility that the flange 06a may fail due to the corrosion. When the flange 06a is damaged, water or the like directly enters into the inner ring 011, and the seal member 07 can not sufficiently seal and water enters into the center bearing 05 to damage the center bearing 05, presenting the possibility that bearing function may be deteriorated, or seizure or noises may occur.
Further, since the stopper piece has the flange and has a varying outer diameter configuration, a cutting process therefor cannot easily be performed, and manufacturing cost is increased because painting is required for preventing corrosion.
Still further, since the stopper piece has the flange and a thickness thereof varies in an axial direction, it is difficult to determine the force for pressing into the propeller shaft, and high accuracy is required.